JP2001233079A - Auxiliary drive for on-board engine - Google Patents

Abstract

(57) [Problem] To provide an accessory drive device for an on-vehicle engine that can further improve the drive efficiency of the accessory. Auxiliary machines provided in an in-vehicle engine and connected so as to be capable of synchronous rotation are rotated by an electric motor that is a power source other than the engine. The electronic control unit 20 calculates the required rotation speeds Mac, Mps, and Mwp, which are the required values of the rotation speed of the electric motor 14 according to the operation requests of the respective auxiliary machines 11 to 13, and sets the maximum value among them as the target. The rotation speed of the electric motor 14 is controlled as the rotation speed Mtr.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an auxiliary driving device for a vehicle engine.

[0002]

2. Description of the Related Art Conventionally, a compressor for an air conditioner (hereinafter referred to as "air conditioner") for compressing a refrigerant for air conditioning in a vehicle, and a power steering for generating a hydraulic pressure for assisting a steering operation related to steering in a vehicle-mounted engine. Various auxiliary devices such as a pump and a water pump for circulating cooling water for the engine are rotationally driven by an engine output shaft. In such a configuration, the accessory is rotationally driven in synchronization with the engine output shaft. Therefore, if the rotation speed of the engine increases, the auxiliary machine is also driven to rotate at an unnecessarily high speed irrespective of the operation requirement, and mechanical loss for driving the auxiliary machine related to the rotation of the engine (auxiliary machine) Loss) is inevitable.

Therefore, as disclosed in Japanese Patent Application Laid-Open No. 4-260831, for example, a power transmission system for driving an auxiliary machine is separated from an engine output shaft, and an auxiliary machine for driving the auxiliary machine by an independent power source other than the engine is used. Machine drive devices have been proposed. In the accessory drive device of the publication, a configuration is described in which a hydraulic motor is used as an independent power source for driving such an accessory. The hydraulic motor generates power by receiving a hydraulic pressure generated by an oil pump, and rotationally drives a plurality of auxiliary machines provided in the vehicle-mounted engine and connected to be rotatable synchronously. Then, the load on the auxiliary machine is detected, and the amount of hydraulic pressure supplied from the oil pump to the hydraulic motor is feedback-controlled to an optimum value according to the load.

[0004] In this way, in the accessory driving device described in the publication, the auxiliary device is driven to rotate without depending on the rotation speed of the engine, so that the accessory loss at the time of high-speed operation of the engine is reduced. Then, the amount of hydraulic pressure supplied to the hydraulic motor is feedback-controlled in accordance with the load of the auxiliary machine, so that each auxiliary machine is driven at a constant rotational speed at which the drive efficiency of the hydraulic motor is maximized.

[0005]

As described above, in the accessory driving apparatus described in the above-mentioned publication, each accessory is rotationally driven at a constant rotation speed at which the driving efficiency of a hydraulic motor as a power source is maximized. Thus, efficient accessory drive is achieved.

[0006] On the other hand, the operation request of each auxiliary machine changes at any time according to the running state of the vehicle, the operating state of the engine, or the operating state of the driver. Therefore, when driving each accessory at a constant rotational speed as described above, the constant rotational speed is set to a certain high speed so that it can respond even when the operation request of each accessory becomes maximum. I have to set it. Therefore, as long as each auxiliary machine is driven at a constant rotational speed, when the operation demand of each auxiliary machine is small, it is undeniable that each auxiliary machine may perform unnecessary work more than necessary. In addition, since it is necessary to ensure the drive efficiency at such a high rotational speed to some extent, there is naturally a limitation in reducing the size and cost of the hydraulic motor as a power source.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide an auxiliary device driving apparatus for an on-vehicle engine which can further improve the driving efficiency of the auxiliary device. .

[0008]

The means for achieving the above object and the effects thereof will be described below. The invention according to claim 1 is an accessory drive device for an in-vehicle engine provided in the in-vehicle engine and rotationally driven by a motive power source other than the engine to drive a plurality of auxiliary devices that are synchronously rotatably connected. For each of the accessories, while calculating the required value of the rotation speed of the corresponding accessory according to the operation request of the corresponding accessory, while satisfying all the calculated required values of the rotation speed of each accessory, There is provided control means for controlling the rotation speed of the power source so that the power source is driven at the rotation speed at which the driving load of the power source is minimized.

In this configuration, a required value of the rotational speed of each of the plurality of auxiliary machines provided in the vehicle-mounted engine and synchronously rotatably driven and connected according to the operation request is calculated. I have. Then, it is possible to satisfy all of the calculated required values of the rotational speeds of the auxiliary machines, that is, to drive each of the auxiliary machines at a rotational speed higher than at least the required value, and the driving load of the power source is minimized. The power source is driven at the rotation speed that becomes Therefore, the rotation speed of the power source is adjusted flexibly in response to a change in the operation request of each accessory according to the running state of the vehicle, the operation state of the engine, the operation state of the driver, and the like. , While reducing unnecessary work of each auxiliary machine more than necessary. Therefore, according to this configuration, it is possible to further improve the driving efficiency of the auxiliary machine.

According to a second aspect of the present invention, there is provided an auxiliary engine driving apparatus for an on-vehicle engine in which a plurality of auxiliary machines provided in the on-vehicle engine and driven and connected so as to be able to rotate synchronously are rotated by a power source other than the engine. In each of the plurality of accessories, a required value of the rotation speed of the power source according to the operation request of the corresponding accessory is calculated, and the calculated rotation speed of the power source for each accessory is calculated. To drive the power source with the maximum value of the values as the rotation speed,
It is provided with control means for controlling the rotation speed of the power source.

[0011] In this configuration, for each of a plurality of accessories provided in the vehicle-mounted engine and drivingly connected so as to be able to rotate synchronously, the required value of the rotation speed of the power source according to the operation request of each accessory, that is, The rotation speed of the power source that can satisfy the operation requirement of the auxiliary machine is calculated. Then, the power source is driven with the maximum value among the calculated required values of the rotation speed of the power source for each accessory as the rotation speed. Therefore, the rotation speed of the power source is adjusted in response to a change in the operation request of each accessory according to the running state of the vehicle, the operation state of the engine, the operation state of the driver, etc. It is possible to reduce unnecessary work of each auxiliary machine more than necessary while securing sufficient power. Therefore, according to this configuration, it is possible to further improve the driving efficiency of the auxiliary machine.

Further, the invention described in claim 3 is the first invention.
Or in the accessory drive device of the vehicle-mounted engine according to 2,
The power source is an electric motor. In this configuration, an electric motor capable of relatively easily controlling the rotation speed is used as a power source for rotating a plurality of auxiliary machines provided in the vehicle-mounted engine and drivingly connected so as to be synchronously rotatable. Therefore, it is easy to implement an auxiliary device driving device for an on-vehicle engine in which the driving efficiency is further improved.

The invention described in claim 4 is the same as the claim 3.
In the auxiliary drive device for an in-vehicle engine described in (1), the electric motor is further connected to the output shaft of the engine so as to be connectable and disconnectable.

In this configuration, the electric motor is connected to the output shaft of the engine, so that the output shaft can be driven to rotate by the electric motor. It can also function as a motor. Therefore, it is not necessary to separately provide a starter motor for starting the engine, and the configuration of the vehicle-mounted engine can be simplified.

[0015]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing an embodiment of an auxiliary driving device for an on-vehicle engine embodying the present invention.

FIG. 1 is a schematic diagram showing the overall structure of the accessory drive device of the present embodiment. FIG. 1 also shows a power transmission system for driving the accessory and an electrical configuration for controlling the drive of the accessory.

As shown in FIG. 1, an engine 10 mounted on a vehicle includes, as auxiliary equipment, a compressor 11 for an air conditioner (hereinafter referred to as an "air conditioner") for compressing a refrigerant for air conditioning in a vehicle, and a vehicle. Oil pump for power steering (hereinafter referred to as "power steering pump") 1 for generating hydraulic pressure for assisting steering operation related to steering
2. A water pump 13 for circulating the cooling water of the engine 10 is provided. And these auxiliary equipments 11
An electric motor 14 is provided as a power source other than the engine 10 that rotationally drives the motors 13 to 13. Each of the above accessories 11 to 1
A belt 15 is stretched between pulleys 11a to 14a provided on the rotating shaft of the motor 3 and the electric motor 14, respectively.

In this embodiment, the belt 15 is also stretched over a pulley 16 which is rotatably disposed on an output shaft (crankshaft) of the engine 10 via a bearing clutch 17. Bearing clutch 17
Disconnects / connects the pulley 16 and the output shaft of the engine 10, and selectively disconnects / connects the power transmission system for rotating the accessory devices 11 to 13 to the output shaft of the engine 10.

The belt 15 is tensioned by a tensioner 18 to drively connect the pulleys 11a to 14a and 16 so as to be synchronously rotatable, thereby transmitting the rotational force of the electric motor 14 to the auxiliary machines 11 to 13. are doing.

In this embodiment, the pulley 16 is connected to the output shaft of the engine 10 by the bearing clutch 17 so that the torque of the electric motor 14 can be transmitted to the output shaft of the engine 10. It is configured. In this embodiment, the engine 10 is started by connecting the bearing clutch 17 and rotating the output shaft of the engine 10 by the electric motor 14. Therefore, in the present embodiment, the electric motor 14 that rotationally drives the auxiliary machine also has a function as a starter motor for starting the engine 10.

The drive control of the electric motor 14 for rotating and driving each of the accessories 11 to 13 is performed by an electronic control unit (hereinafter referred to as “EC”).
U ") 20. The ECU 20 is composed of a series of electronic circuits that control the operation of the engine 10, the running control of the vehicle (shift control, power steering control, etc.), the air conditioning control of the vehicle interior, and the like. The rotation speed of the electric motor 14 is controlled.

The ECU 20 also stores operating conditions of the engine 10, running conditions of the vehicle, operating conditions of the auxiliary equipments 11 to 13, operation of the driver related to running of the vehicle and an air conditioner, and the environment (temperature, An output signal of various sensors and switches 21 for detecting the amount of solar radiation, etc.) is input. The ECU 20 obtains the required operation amount of each of the auxiliary machines 11 to 13 based on the detection results of these various sensors and switches, and controls the electric motor so as to be driven at an appropriate rotation speed according to the required operation amount. 14 is controlled.

Hereinafter, the control of the rotation speed of the electric motor 14 for driving the auxiliary equipment will be described in detail with reference to FIG. FIG. 2 shows an appropriate electric motor 14 according to the operation request of each of the auxiliary machines 11 to 13 in the present embodiment.
"Rotation speed calculation routine" for calculating the rotation speed of the motor
It is a flowchart of FIG. This routine is periodically executed by the ECU 20 at predetermined time intervals.

When shifting to this routine, the ECU 20
First, in step 10, the detection results of various sensors, switches and the like 21 necessary for obtaining the required operation amount of each of the auxiliary machines 11 to 13 are read. And the following step 20
, A required value of the rotation speed of each of the auxiliary devices 11 to 13 according to the operation request grasped based on the read detection result, that is, the required rotation speed Nac of each of the auxiliary devices 11 to 13,
Nps and Nwp are calculated.

The required rotational speed Nac of the air-conditioner compressor 11 includes a set temperature of the air conditioner, a vehicle interior temperature (room temperature) detected by a room temperature sensor, an outside temperature (outside air temperature) detected by an outside air temperature sensor, and a pressure sensor. Is calculated based on the pressure of the refrigerant (compressor pressure) compressed by the compressor 11 detected by the compressor. It is determined that the higher the outside air temperature, the higher the room temperature is higher than the set temperature, or the lower the compressor pressure, the higher the operation requirement of the compressor 11 for the air conditioner. Nac is set to a higher speed.

The required rotation speed Nps of the power steering pump 12 is detected by a vehicle speed (vehicle speed) detected by a vehicle speed sensor, a steering operation amount (steering angle) detected by a steering angle sensor, and a hydraulic pressure sensor. Is calculated based on the hydraulic pressure (pump hydraulic pressure) generated by the power steering pump 12. And this power steering pump 12
It is determined that the lower the vehicle speed, the larger the steering angle, or the lower the pump oil pressure, the higher the operation requirement is, and the required rotation speed Np of the power steering pump 12 is determined.
s is set to a higher speed side.

Further, the required rotation speed Nwp of the water pump 13 includes the temperature (water temperature) of the engine cooling water detected by the water temperature sensor, the rotation speed of the engine 10 detected by the rotation speed sensor, and the throttle detected by the throttle sensor. It is calculated based on the valve opening (throttle opening) and the like. And this water pump 13
It is determined that the higher the water temperature, the higher the rotation speed of the engine 10, or the larger the throttle opening degree, and thus the greater the load on the engine 10, the higher the operation requirement. N
wp is set on the higher speed side.

After calculating the required rotational speeds Nac, Nps and Nwp of the respective auxiliary machines 11 to 13 in this way, the ECU 2
If the value is 0, the process proceeds to the subsequent step 30. In this step 30, the required rotation speeds Nac,
The required value of the rotation speed of the electric motor 14 corresponding to each of Nps and Nwp, that is, the required rotation speeds Mac, Mps, and Mwp of the electric motor 14 for each of the accessories 11 to 13 is calculated. Here, assuming that the pulleys 11a to 14a driven and connected through the belt 15 rotate completely synchronously, the required rotation speeds Mac, Mps, and Mwp are equal to those of the auxiliary machines 11 to 13 with respect to the pulley 14a of the electric motor 14. The ratio between the diameters of the pulleys 11a to 13a and the required rotational speed Na
It can be easily obtained from c, Nps and Nwp.

Thereafter, in the subsequent step 40, the ECU 20 calculates the required rotational speeds Mac, Mp
The maximum value of s and Mwp is set as the target rotation speed Mtr of the electric motor 14, and the processing of this routine is temporarily ended. Then, the ECU 20 controls the rotation speed of the electric motor 14 so that the rotation speed of the electric motor 14 becomes the calculated target rotation speed Mtr. Therefore, the electric motor 14 is driven with a minimum rotation speed, that is, with a minimum drive load, while satisfying all the operation requirements of the respective auxiliary machines 11 to 13.

Incidentally, depending on the characteristics of the electric motor 14,
If the rotation speed is set too low, the efficiency of the electric motor 14 may deteriorate, and the driving efficiency of the auxiliary machines 11 to 13 may decrease. In such a case, it is desirable to set a lower limit value for the rotation speed of the electric motor 14 so that the target rotation speed Mtr falls within a range of the rotation speed at which the efficiency of the electric motor 14 can be sufficiently ensured.

According to the accessory drive device for an onboard engine of the above embodiment, the following effects can be obtained. (1) In the above-described embodiment, a plurality of auxiliary devices 11 to 13 provided in the vehicle-mounted engine 10 and connected so as to be rotatable synchronously are provided.
Are driven by an electric motor 14, which is a power source other than the engine 10, in the accessory drive device of the in-vehicle engine, the required rotation speeds Nac and Nps, which are the required values of the rotation speeds of the respective accessories 11 to 13 according to the operation request. , Nwp are calculated for each of the auxiliary machines 11 to 13, and the rotation speed at which the driving load of the electric motor 14 is minimized while satisfying all of the calculated required rotation speeds Nac, Nps, Nwp. Target rotation speed Mtr
, The rotation speed of the electric motor 14 is controlled.
Therefore, it is possible to flexibly cope with a change in the operation demand of each of the auxiliary devices 11 to 13 and secure unnecessary power for each of the auxiliary devices 11 to 13, while performing unnecessary work more than necessary for each of the auxiliary devices 11 to 13. Can be reduced. Therefore, it is possible to further improve the driving efficiency of the auxiliary machines 11 to 13.

(2) In the above embodiment, each of the auxiliary machines 11 to 1
The required rotation speeds Mac, Mps, and Mwp, which are the required values of the rotation speed of the electric motor 14 according to each of the three operation requests, are calculated for each of the auxiliary devices 11 to 13, and the required rotation speeds Mac, Mps, and Mwp are calculated. The maximum speed MAX (Mac, Mps, Mwp) is set as the target rotation speed Mtr of the electric motor 14, and the rotation speed of the electric motor 14 is controlled. Therefore, the rotation speed of the electric motor 14 is adjusted flexibly in response to a change in operation demand, and
While securing the power required for 1 to 13, each auxiliary device 11 to 1
3) Unnecessary extra work can be reduced. Therefore, it is possible to further improve the driving efficiency of the auxiliary machines 11 to 13.

(3) In the above embodiment, the onboard engine 1
An electric motor 14 whose rotation speed can be relatively easily controlled is used as a power source for rotating a plurality of auxiliary machines 11 to 13 provided in the motor 0 and driven to be synchronously rotatable. Therefore, it is easy to implement the accessory drive device of the vehicle-mounted engine 10 that further improves the drive efficiency as described above.

(4) In the above embodiment, the electric motor 14
Is further connected to the output shaft of the engine 10 so as to be connectable and disconnectable. Then, the electric motor 14 is connected to the engine 1
0, the engine output shaft can be driven to rotate by the electric motor 14, so that the
The electric motor 14 for driving the motor 13 can also function as a starter motor for starting the engine. Therefore, there is no need to separately provide a starter motor for starting the engine, and the configuration of the vehicle-mounted engine 10 can be simplified.

The above embodiment may be modified as follows. The method for calculating the required rotational speeds Nac, Nps, Nwp of the respective auxiliary machines 11 to 13 in the above embodiment, or the respective auxiliary machines 1
Required rotation speed Ma of electric motor 14 for 1 to 13
The calculation method of c, Mps, and Mwp is an example, and may be arbitrarily changed according to the configuration of the in-vehicle engine 10 and the accessory driving device to be applied.

In the above-described embodiment, the auxiliary device driving device for the vehicle-mounted engine including the air conditioner compressor 11, the power steering pump 12, and the water pump 13 has been described as the auxiliary device that is rotated and driven by the electric motor 14, but the configuration of the auxiliary device The present invention can also be applied to an accessory drive device including an accessory such as a negative pressure pump or a fuel pump for generating a negative pressure, in addition to the accessories 11 to 13 described above.

In the above embodiment, the electric motor 1
The drive motor 4 is connected to the output shaft of the engine 10 so as to be connectable and disconnectable so that the electric motor 14 also functions as a starter motor for starting the engine. The effect described in (3) can be obtained.

In the above-described embodiment, the electric motor 1 is used as a power source other than the engine 10 for rotating the auxiliary machine.
4, the power source may be any power source other than the engine 10, such as a hydraulic pump.

[Brief description of the drawings]

FIG. 1 is a schematic diagram schematically showing the entire structure of an embodiment of the present invention.

FIG. 2 is a flowchart of a rotation speed calculation routine used in the embodiment.

[Explanation of symbols]

10: on-board engine, 11: compressor (auxiliary equipment), 1
2 ... oil pump (auxiliary equipment), 12 ... power steering pump (auxiliary equipment), 13 ... water pump (auxiliary equipment), 14 ... electric motor (power source), 15 ... belt, 11a to 14a, 16 ...
Pulley, 17: bearing clutch, 18: tensioner, 20: electronic control unit (control means), 21: various sensors and switches.

Claims (4)

[Claims] An accessory drive device for an in-vehicle engine provided in the in-vehicle engine and rotationally driven by a power source other than the engine, the plurality of accessories being driven and connected so as to be able to rotate synchronously. With regard to the above, while calculating the required value of the rotation speed of the corresponding auxiliary machine according to the operation request of the corresponding auxiliary machine, and satisfying all the calculated required values of the rotation speed of each auxiliary machine, the driving of the power source is performed. An auxiliary drive device for an in-vehicle engine, comprising control means for controlling a rotation speed of the power source so as to drive the power source at a rotation speed at which a load is minimized. 2. An accessory drive device for an in-vehicle engine provided in the in-vehicle engine and rotationally driven by a power source other than the engine, the plurality of accessories being driven and connected to be rotatable synchronously. The required value of the rotation speed of the power source according to the operation request of the corresponding accessory is calculated, and the maximum value of the calculated required values of the rotation speed of the power source for each accessory is calculated as the rotation speed. And a control unit for controlling a rotation speed of the power source so as to drive the power source. 3. The power source according to claim 1, wherein the power source is an electric motor.
Or an auxiliary drive device for an in-vehicle engine according to item 2. 4. The accessory drive device for an on-vehicle engine according to claim 3, wherein the electric motor is further connected to the output shaft of the engine so as to be connectable and disconnectable.